The field of this invention is that of fuel filters for diesal engines and the invention relates more particularly to a filter system having a heater to prevent cold whether clogging of the filter.
In that regard it is found that although diesel fuels as presently sold are intended to meet desired standards, paraffin residues and the like which remain in the fuel may tend to solidify in the fuel while the fuel is in the fuel tank or filter system when the vehicle is standing idle during cold weather. Thereafter, when engine operation is initiated, those solidified fuel components can temporarily clog the fuel filter system causing poor engine performance particularly during engine starting. Where diesel engines are now becoming more widely used in automobiles they are desirably adapted for more trouble-free operation by nonprofessional drivers who are less likely to be able to cope with such filter clogging problems and the like. For this reason, it would be desirable to provide a diesel fuel filter heater to prevent such filter clogging particularly if such an improvement could be achieved at reasonable cost in a manner which would not impose undue drain on the electrical power supply capacity of the vehicle. Further, where such a heater is primarily useful during engine start up, the heater should be adapted to permit relatively free flow of fuel to the engine during engine start up and thereafter during normal running operation of the engine.
It is an object of this invention to provide a novel and improved diesel fuel filter heater; to provide such a heater which uses low cost components; to provide such a heater which is easily accommodated in conventional fuel filter systems; to provide such a heater which is operable without excessively loading the power supply capacity of a diesel-powered vehicle; and to provide such a heater which permits relatively free flow of fuel through the heater to the engine during engine start up and thereafter.